Is there an option to log all individual PPS events?

The $100 for a Pi might be significantly low.  It depends on what you have in
your toy box.

Aside from the Pi and GPS HAT, you also need power and a micro SD card.  For
black box applications, you probably want a case.  You may need an external
GPS antenna.

For getting started, you also need:
SD card reader/writer
keyboard and mouse (Pi has USB)
display adapter (Pi is HDMI)
display

I have an old KVM switch.  It uses PS2 rather than USB, so I need a PS2 to
USB adapter.

--
These are my opinions.  I hate spam.

A black box was asked for. Who cares what the OS inside is if you never
need to mess with it. A surprising number of things run linux variants.
Pretty much every smart phone is linux or unix...

What is the output format you would like for your timestamp? disk, network
file system, serial all can be made to work.

One could probably build 10-20 for a couple thousand dollars and make
enough to make it worth the trouble, depending on the output format of the
timestamp.

Pi Zero - $10
SD card - $8
GPS - $4
2x16 LCD display - $5
Enclosure - $15 for small box, $20 for ABS rack mount, $35 for aluminum
Hardware, nuts, bolts, screws, etc - $5
Power Supply - $5
Custom Interface card with buffering for TTL signal, other signal input
method, opto isolator, serial port for config & control, rs-232 out for
timestamp, serial and PPS from GPS, connectors, etc - $20-25 built.
Cables, etc - $5
Small rubber duck or GPS puck antenna $5

Ethernet, add $25.

Pi has USB/HDMI, but you can run it headless too.

Total BOM ~$100 (expensive case)
Development - ~week @$75/hr = $3,000 (board design, prototype, code +
documentation)
Manufacturing, packaging, etc ~$50/unit

Shipped cost/unit, 20 units = $150materials, $150 labor = $300.
40 units = $225

Obviously BOM costs go down w volume, but you'd have to hit at least
quantity 50 to get a good break on enclosures and the custom boards.

So the big variable is how many will you need and what are you willing to
pay the developer. $75/hr is more or less going contract rates in my world.
$125-$150 not unheard of.

One off, no labor cost, cheap. Under $40 if you provide your own enclosure,
antenna, etc.

On Wed, Oct 18, 2017 at 3:26 PM, Hal Murray hmurray@megapathdsl.net wrote:

Yo Hal!

On Wed, 18 Oct 2017 12:26:27 -0700
Hal Murray hmurray@megapathdsl.net wrote:

# ppswatch /dev/pps0
trying PPS source "/dev/pps0"
found PPS source "/dev/pps0"
timestamp: 1508356708, sequence: 591837, offset:  1412510
timestamp: 1508356709, sequence: 591838, offset:  1381010
timestamp: 1508356709, sequence: 591838, offset:  1381010
timestamp: 1508356710, sequence: 591839, offset:  1397496
timestamp: 1508356710, sequence: 591839, offset:  1397496

Just redirect to a log file.

Looking at Amazon, quantity one, I see:

RasPi3 $35
GPS Hat w/ remote antenna and cord: $30
16BG miscro sd card: $9
RaspI + HAT case: $10
USB charger: $8
USB charge cable: $2
Cat5 ethernet cable: $2

Looks like $96 to me.  You can save some if you buy in bulk,

Plus labor, which after the first one is small.

Yeah, just for setup.  Shall we include the price of the desk it sits
and the building it is in?

RGDS
GARY

Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
gem@rellim.com  Tel:+1 541 382 8588

    Veritas liberabit vos. -- Quid est veritas?
"If you can’t measure it, you can’t improve it." - Lord Kelvin

On Wed, Oct 18, 2017 at 9:11 PM, Gary E. Miller gem@rellim.com wrote:

You can set a Pi up headless from scratch by putting an empty file called
'ssh' in the boot directory of the raspbian SD card. It then enables the
ssh daemon on startup.

Of course, then you need another computer to talk to it with ..

Perhaps less  :

http://www.ebay.co.uk/itm/122596979464

On 10/18/17 2:09 PM, Adrian Godwin wrote:

This is one of the reasons I use beaglebone greens - soldered in eMMC so
no need for SD card, no HDMI interface - the expectation is that you're
using it headless/serial console style. And the eMMC is preloaded with
Debian Jessie (or perhaps something newer)

The only ugly thing is the USB Gadget interface, which works fine, but
always seems a bit weird - The USB serves triple duty - disk access to
part of the file system, IP network interface, serial console port.

So on a Mac, you can mount it as a disk, ssh or "screen" to it via
either ip or the /dev/cu.usbmodem

There's also a standard ethernet interface. Which by default comes up
using DHCP and zeroconf, so you can plug it in to your network at home,
and then look for it with "ping beaglebone.local".

And the beaglebone has lots of GPIO.

Unless you're a real hardcore embedded person, in which case you just
make and break a connection between two wires on the TxD line to send
ascii, and you use the blinks of an LED or the intermittent tingle on
your tongue from the RxD to decode it.